Formula of definite point overburden pressure of reservoir layers

Overburden pressure, P_ob, is pressure imposed on layers during the different hydrocarbonic layers operations by the weight of overburden layers. Practically, the geological layers structure varies in matrix and porous media during well head treatment operations such as acidizing, hydraulic fracturing and fluid injection when drilling and completion. So, three structural quantity inter-granular space (IGS), inter-fracture space (IFS) and fracture width (FW) affect fluid conductivity and layers P_ob alternations.Using the petrophysic and geological information and the content of tables under the reservoir conditions, P_ob was formulated for a drilled layer point in various porosity ranges.Since reservoir layers mostly have heterogeneity characterizations, and timely and repeatedly need to control the type of cutting lithology, drilling mud and reservoir pressure by geologists and drillers, the equations derived are effective in wellhead and bottom hole operations for the calculations in which the overburden pressure plays a key role.